Digital Electronics Basics

• Electrical engineering is a professional engineering discipline that generally deals with the study and application of electricity, electronics and electromagnetism (higher voltages)
• Electronic engineering is a branch of electrical engineering where we work on low voltage devices such as semiconductors, transistors, diodes, integrated circuits.
• In electronic engineering we study two types of systems: analog and digital system.

Difference between digital and analog system

• Analog system: continuous value is used to denote the information. Analog signals is defined as any physical quantity which varies continously with respect to time, e.g. apmlifier, ecg, watch, radio, etc.
• Digital system: information is denoted by a finite sequence of discrete values or digits. Digital signals is defined as any physical quantity having discrete values, e.g. digital watch, calculator, bp machine, thermometer, etc.

Advantage of digital system ↓

• Digital system are easy to design because they do not require sound engineering and mathematical knowledge, uses only switching circuits.
• Storage for long time and processing of information is easy.
• They provide better accuracy and precision.
• Less affected by noise like sound electric field, magnetic field.
• Better modularity and easy fabrication, it means size will be vary small, e.g. IC.
• Less cost.

Importance of digital system

• Digital system have sucha prominent role in everyday life (digital age).
• Digital system used in communication, business, traffic control, space guidance, medical, industry, science, etc.

Lets try to understand designing of digital device using which we will understand the entire process.

Q- Design a warning system for a car manufacturing company with three inputs light, day, engine?

• Steps to remember
  1. Understand problem
  2. Design a truth table
  3. Write boolean expression
  4. Minimize boolean expression
  5. Implement using logic gates

• After making table next step is to write a boolean expression.
• Boolean expression in easy words: we have to remember where we have either 0 or 1.

• Between SOP and POS which is prior?
  • Use whichever has the minimun elements.
  • But minterms are more friendly so we usually use it.
• Boolean expression ↓

• After making expression we have to make a circuit which should be less costly. To minimize the cost we use process like K-map, etc.